Alligatoring on Flat Roofs

Schedule a Free Roof Evaluation


A pattern of cracks similar to an alligator’s hide.

Cracking of the surfacing bitumen on a bituminous roof or coating on a SPF roof, producing a pattern of cracks similar to an alligator’s hide. The cracks may not extend completely through the surfacing bitumen or coating. When left unattended, cracks and splits eventually develops. Water will enter the roofing system and cause unseen damage in the roof system. As the surfacing layer fails, the fiberglass reinforcement underneath is exposed and becomes brittle. Membrane failure inevitably follows.

Alligatoring is commonly found on smooth surface asphalt roofs. It is caused by the drying out of the exposed asphalt surfacing by the sun. When the defects are tiny, it's referred to as checking.

Smooth built up roofs should be inspected annually for damage. A roof coating may be applied to reflect harmful ultraviolet rays and reduce thermal cycling.

How to Repair Alligatoring

This roof repair procedure only applies to mild alligatoring on a built up roof. Areas with deep cracks will need too much product and you may be better off with other alternatives. Don't hesitate to call us for technical support. Advice is free, replacement is costly.

Steps for Fixing Alligatoring

  1. Thoroughly clean the roof area to be repaired. If the alligatoring is all over the roof, pressure washing is recommended.
  2. Small hairline cracks can be filled simply by applying EnergyGuard Aromatic Polyurethane and working it in with a roller or putty knife. For larger areas, you can embed SeamStitch Polyester Fabric into the coating and create a smoother, reinforced surface.

Get A Free Estimate

Bio Pro Research
Bio Pro Research

Newton, NC

Badly deteriorated EPDM roof was leaking everywhere. They were able to fix all the leaks with just one coat of EnergyGuard Aromatic Polyurethane.

Andersen AFB 19020

This newly constructed 18,800sf building at the Andersen AFB in Guam has a concrete roof primed with PrimeLock Epoxy Primer and coated with 45 dry mils of EnergyMax Silicone Coating to keep it cool and leak-free.

March Air Reserve Base
March Air Reserve Base

March ARB, CA

A seamless, watertight Lexis silicone coating system on the modified bitumen roof of March Air Reserve Base in California fixed all roof leaks.

Base Exchange
Base Exchange

Andersen AFB, GU

Structural cracks on this concrete roof required a custom, lab-tested solution. Lexis Silicone Coatings not only delivered. We exceeded.

CT Walker School
CT Walker School

Augusta, GA

Seamlessly Beautiful. CT Walker was looking for a high build roof coating with the same brick red color as the rest of the school.


Atlanta, GA

Air conditioning can account for 30% of the operating costs of a business. Roof Coatings reflect up to 90% of the sun's heat.